Low-temperature distillation of bituminous coal



Jan. 15, 1929. 1,698,907

R. H. CARR ET AL LOW TEMPERATURE DISTILLATION OF BITUMINOUS COAL Filed April 15,. 1926 (567/ t5 Zlwucntot .Zichardfl Carr I (orneliws' B. 74 222160);

mama Jan. '15, 1929.

UNITED STATES PATENT OFFICE.

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Application fled April 15,1926. Serial no. 102,832.

This invention relates to the coking of coal under conditions of low temperatures and pressures, and comprises a method of utllizing bituminous coal and like solid fuels for' the production of coke and by-productswhich consists in positively advancing coal in an upward direction through a closed'tower or retort, wherein the temperature of the coal is gradually raiseduntil the coal reaches the I upper or hottest portion of the to er, the

heating of the coel being accom lish d, preferably, through the medium 0 introducing superheated steam or heated oil vapors into the top of the tower and into intimate contact with the coal therein, at which point the coke is removed from the tower, the liberated vapors and other gases, due to distillation, being removed fromthe coal between its point of introduction and the coke outlet;

It is an object of the present invention to provide a method of dlstilling bituminous.

coal by an economical and efiectlve process so asto secure therefrom by-products in the form of hydrocarbon ases and vapors and to obtain fromthese sue commercial products as distillate, lubricating oils, waxes and the like in addition to thecokfe. Under the action of the superheated steam or oil vapor introduced into the top of the retort and, in

opposition to the upwardly moving coal, the vaporization of the volatile content of the coal is eflected; these products being removed from the coal at a point between the relatively cool and heated portionsof the retort. In order to obtain any large yield of the by-products throu h dlstilling coal a careful adjustment of t ermal and other .conditions must be made. The temperature of the coal should becaused to ri'seprogressively and gradually through rangesup to the working limits of superheated steam or oil vapor.

Volatiles will be removed fromthe-point of .iormation by progressin downwardly and thereby, encountering co der temperatures causing condensation of said volatiles and permitting of their. independent remova from'the tower.

In what we regard as the preferred .embodiment of our invention, we employ a tower or retort having means for introducing the coal into the bottom thereof, and for positively adtemperatures to extract therefrom the more volatile hydrocarbon products thereof and to reuse the temperature of the coal sufiiciently to produce the desired grades of coke. In

the present invention it is desirable to avoid the cracking or decomposition of the h drocarbons initially distilled from the coa ,and

for this reason we find it practical to employ superheated steani in effecting the processof distillation, except under conditions wherein we use the vapor. of a distillate containing heavy hydrocarbon fractions as a heatin mediumfor the coalinstead of using su er eated steam, in which case the heavy ractions are referabl subjected to decomposition to obtam a maximum tions.

In the accompanyinfi drawing there is disclosed diagrammatica y and in vertical secyield of the lighter fraction a form of apparatus forcarrying out the present invention. a

In this drawing, the numeral 1 designates a tower or retort, comprising an enlar ed funnel shaped body in which the coal un ergoing process 'of distillation and coking is maintained, and the lower end of the ,tower is formed to provide arestricted coal inlet 2. For purposes of illustration, the inlet of the tower is provided with a charging magazine structure 3, consisting of a plurality of conveyors 3' operating in-a water filled casi 3' by-which the coal is capable of be-' ing orced upwardly into and through the tower in a positively actuated, slowly and progressively moving manner, with the gases sealed against loss,

The walls 4' of. he tower define a distilling and'fcoki'ng chamber 5 which may be of any suitable eapacity holding for example in comnercial installations'from fifty to one hun- 'dred tons'Eof coal, whereas the inlet may be constructed toicontain ap roximately one ton per charge of coal. At t e top of the tower there is provided in this instance a coil 6, con- 'nected with an exteriorly arranged steam pipe 7 having a control valve 8 disposed therein. In this form of the invention superheated steam under temperatures of, for example, from 750 to 800 degrees Fahrenheit may be introduced into the tower and preferably at or near the upper end thereof to heat the contents of the chamber 5. It is within the scope of the invention to use the vapors released from heated fractions of high boiling point, and when such oil vapors are used the temperatures necessarily will 'be somewhat higher than those given hereir'iwhen superheated steam is utilized.

The superheated steam or oil vapor is directly applied to the top of the body of coal contained in the tower and the heat thereof is allowed to permeate through the ascending body of coal in said chamber, so thatthe temperature of the coal willbe gradually and progressively raised. Before the coal is subjected to the highest temperatures the lighter portions of the hydrocarbon gases, vapors and liquids, which may be said to constitute the primary volatiles, are released from the coal and flow downwardly in counter currentdirection to the ascending column of coal, thereby vaporizing or condensing said volatiles so that the latter may find exit from the tower byway of the tuyere construction 9, or through the water containing inlet of the tower. It will be understood that one or more of the tuyere outlets may be provided between the inlet 2 and the heated zone 10 in the top-of the apparatus. These vapors or liquids may be then led to suitable condensin and separating apparatus (not shown) an reduced to various commercial products such therein control the extraction of the primary volatiles'from a quantitative standpoint, and it is thepurpose of the present invention to employ low temperatures so that the extraction of the volatiles will not effect the commercial grade of the finally produced coke. The bottom of the outlet 11 terminates in .a

liquid. sealed container 12, which receives and quenches the coke released from the outlet 11, but fillOWSrthB steam generated during this as f operation 'to' travel upwardly through said outlet and into' the interior of the tower 1, where 'it is used in the heating of the coal.-

" In view of the foregoing it will be seen that the present invention embodie' a process of distilling coal unique in the operation of advancing. coal in 'anupward direction through a tower and wherein the temperature recovery of the coal is gradually raised until coke is formed by the higher temperatures prevailing in the upper part of the tower, the primary volatiles produced during this operation being released from the tower between the point of coal inlet and the point of coke outlet of the tower. Moreover, the quenching of the coke is effected in such manner as to permit the steam released therefrom to enter the tower and heat the materials therein. These features all contribute toward an economically operating system by which the of the primary volatiles is renderedcommercially profitable.

While we'hav'e referred specifically in both the description and the following claims to a heating medium in the form of superheated steam or oil vapors, it is intended that these expressions shall be construed to cover any gaseous or vaporous heating medium suit able for the purposes of distillation and which is chemically inert with respect to the fuel body.

What is claimed is:

1. The method of producing coke and distillation products from coal by low temperature distillation and without active combustion, which consists in forcing a body of such fuel in an upward direction through a closed receptacle, introducing into the upper part of said receptacle a gaseous heating medium in the form of superheated steamunder temperature conditions suflicient to coke the fuel body in the upper portion of said receptacle without combustion, in removing .a certain portion of the primary products of distillation from the fuel body at a point between the fuel inlet and coke outlet of the recep-" tacle, said products of distillation being caused to traverse the fuel body in a direction counter-current to the direction of travel of the fuel body prior to the release of the products of distillation from said receptacle, and in separately removing the coke from said receptacle.

2. The method of producing coke and distillation products from coal by low temperature distillation and without active combustion, which consists in forcing a body of such fuel upwardly through a closed receptacle, subiecting the top of the fuelbody within said receptacle to a gaseous heating medium in the form ofsuperheated steam to change the composition of the fuel to that of low tem perature coke without active combustion on the part of the fuel body, in removing the formed cokefrom thereceptacle, and in withdrawing from the upwardly moving body of fuel within the receptacle the primary distillates at a position below the coke outlet, said distillates being caused to traverse said fuel body in a direction opposed to the direction of movement of said fuel body prior to the release of the distillates from the receptacle.

.3. The method'o'f-producing coke and distillation'plroducts from coal by low temperaturedist atioxi and without active combustion, which consists in forcing a body of such fuel in an upward directionthrough a closed receptacle, introducing into theupper part of said receptacle a gaseous heating medium in the form of superheated steam under tem peratureconditions suflicient to coke the fuel body in the upper portion of said receptaclewithout combustion, in removing a certain portion of the primary products of distillationfrom the fuel body at a point below the coke outlet of the receptacle, said products of distillation being caused totransveg'se the moving the coke from said receptacle, the

.fuel body at no time during its passage through the receptacle being heated to a temperature in excess of 1000? Fab.

4. The method of producing coke and distillation products from coal by low temperature distillation and without active combustion, which consists in forcing a body of such fuel in an upward direction through a closed receptacle having a coal inlet and a coke out let, said receptacle being sealed against the escape of internal fluids, introducing a gaseous heating medium chemically inert with respect to the fuel into the receptacle at the top of the fuel'body and into direct contact with the fuel body, the heat derived from said heating medium being such as to effect decomposition of the fuel body without combustion to release the primary distillates thereof, inremoving the formed coke from the top of said body, and in causing the primary vdistillates to traverse the .fuel body in a direction opposed to the positive advance tillation productsfrom coal by low temperature distillation and without active combusof the fuel body through the receptacle, saidprimary distillates being removed from the receptacle at a'posit-ion below the coke outlet. 5. The method of producing cokeand dis tion, which consists in forcing a body of such fuel in an upward direction through a closed receptacle having a coal inlet and a coke outlet, said -.receptacle being sealed against the escape of i nternal fluids, introducing a gaseous heat ngmedium havin the properties.

I of superheated steam into t e receptacle at the top of the fuelbody and into. direct contact with the fuel body,- the heat derivedfrom said heating medium being such as to effect decomposition of the'fuel body without combustlonto release the primar distillate's thereof in removing the forme coke from the top of said body, and in causin the primary distillates to traverse the fuel %ody in a direction opposed to the positive advance ofthe fuel body through the receptacle, said primary distillates being removed from the tion suita ing a gaseous heating medium into the re:

receptacle at a position below the coke out: let, the fuel body at no time during its passage through -the receptaclebein heated to a temperature in excess of 1000 iah. 6. The method of producing coke and distillation products from-coal by low tempera ture distillation and without ,active 'combustion, which consists in positively moving a body of such fuel in an u ward direction through aclosed receptac e having outwardly flaring walls to provide an increase in diameter from the bottom towards the top,

introducing a gaseous heating medium into said receptacle at the top of the fuel body to effect decomposition of the fuel body without ,combustion of the coke and primary distillates, the primary distillates produced by heating the fuel body being caused to travel through the fuel body in a direction opposed to the upward travel of thefuel body, in removing the formed cokefrom the top of the maintaining the topofthe coal body -within said receptacle in an open perviouscondition suitable for heat penetration, introducing a gaseous heating medium into the receptacle T at the top of the coal body, the heating medium being maintained under such conditions of temperature and pressure that the' same way penetrate into the upwardly movin body of coal to'decompose the latter into co e and primary distillates, removing coke from the top of the fuel body and in removing the distillation products at positions ma-. terially below the coke outlet, said distillation products being caused to traverse the coal body in counter-current relationship to the direction of'movement ofsaid coal body.

8. The method of producing coke and distillation products from coal by low temperature distillation and without active combustion, which consists in'introducing the coal:

into a closed receptacle and advancing the same, upwardly 'thro h saidreceptacle,- maintaining the top of the coal body within said rece tacle in an'open pervious condi- $316 for heat penetration, introducceptacle at the top of the coal body, the heating medium being maintained under such conditions of temperature pressure that the same may penetrate intothe upwardly moving body of coal todecom ose the latter into coke and primary disti ates, removing coke from the top of the fuel body and in re-' passage through the receptacle being heated moving thedistillation products at positions to a temperature in excess of 1000 Fah. v materially below the coke outlet, said dis- In testimony whereof we afix our signa- 10 tillation products being caused to traverse tures.

5 the coal body in counter-current relationship to the direction of movement of said 'coal RICHARD H. CARR. body, the fuel body at no time during its CORNELIUS B. WATSON. 

